Albert Jay Nock (October 13, 1870 – August 19, 1945) was an American libertarian author, editor first of The Nation and then The Freeman, educational theorist, Georgist, and social critic of the early and middle 20th century. He was an outspoken opponent of the New Deal, and served as a fundamental inspiration for the modern libertarian and conservative movements, cited as an influence by William F. Buckley Jr. He was one of the first Americans to self-identify as "libertarian". His best-known books are Memoirs of a Superfluous Man and Our Enemy, the State.

Throughout his life, Nock was a deeply private man who shared few of the details of his personal life with his working partners. He was born in Scranton, Pennsylvania, the son of Emma Sheldon Jay and Joseph Albert Nock, who was both a steelworker and an Episcopal priest. He was raised in Brooklyn, New York. Nock attended St. Stephen's College (now known as Bard College) from 1884 to 1888, where he joined Sigma Alpha Epsilon fraternity.

After graduation he had a brief career playing minor league baseball, and then attended a theological seminary and was ordained as an Episcopal priest in 1897. Nock married Agnes Grumbine in 1900 and the couple had two children, Francis and Samuel (both of whom became college professors). In 1909, Nock left the ministry as well as his wife and children, and became a journalist.

In 1914, Nock joined the staff of The Nation magazine, which at the time was more aligned with liberal capitalism. Nock was an acquaintance of the influential politician and orator William Jennings Bryan, and in 1915 traveled to Europe on a special assignment for Bryan, who was then Secretary of State. Nock also maintained friendships with many of the leading proponents of the Georgist movement.

However, while Nock was a lifelong admirer of Henry George, he was frequently at odds with other Georgists in the left-leaning movement. Further, Nock was influenced by the anti-collectivist writings of the German sociologist Franz Oppenheimer, whose most famous work, Der Staat, was published in English translation in 1915. In his own writings, Nock would later build on Oppenheimer's claim that the pursuit of human ends can be divided into two forms: the productive or economic means, and the parasitic, political means.

Between 1920 and 1924, Nock was the co-editor of The Freeman. The Freeman was initially conceived as a vehicle for the single tax movement. It was financed by the wealthy wife of the magazine's other editor, Francis Neilson, although neither Nock nor Neilson was a dedicated single taxer. Contributors to The Freeman included: Charles A. Beard, William Henry Chamberlin, Thomas Mann, Lewis Mumford, Bertrand Russell, Lincoln Steffens, Louis Untermeyer, Thorstein Veblen and Suzanne La Follette, the more libertarian cousin of Senator Robert M. La Follette. Critic H.L. Mencken wrote:

His editorials during the three brief years of the Freeman set a mark that no other man of his trade has ever quite managed to reach. They were well-informed and sometimes even learned, but there was never the slightest trace of pedantry in them.

When the unprofitable The Freeman ceased publication in 1924, Nock became a freelance journalist in New York City and Brussels, Belgium.